Cellulose composition



Patented May 6, 1924.

UNITED STATES' P ATE/NT 1 WILLIAM G. LINDSAY, or NEWARK, NEW JERSEY, assIGN-oR 1T0 THE 'cE LuLo-rn 'coMPANY, A CORPORATION OF NEW JERSEY. r i; 1

cELLULosE COMPOSITION.

1 1 Drawing. Original application filed April 25, 1922, Serial No. 556,531. inviaai'g nc' tnisap1ic tinfiled March 13,1923. Serial No. 624,701. 7,,

To all whom it mag concern: I Be it known that I, WILLIAM G. LIrInsAY, a citizen of the United States, resldmg at f Newark, in the county of Essex and State 5 of New-Jersey, have invented certain new and useful Improvementsin Cellulose Compositions, of which the following is a specification. I

This invention relates to a process for rendering certain inflammable materials, substance, or compounds, non-inflammable,

and to the preparation of commerciallyuse ful, non-inflammablearticles, such as paper, textile fabrics, cellulose plastics and the like. The degreeof non-inflammability sought sustaining combustion, after the application of a flame at ordinary or normal tempera.

ture. This degree of non-inflammability will however, be varied according to desired conditions. I

Iv have discovered that inflammable materials which permit of a self sustaining com-- 26 bustion by the application of a flame at ordinary or normal temperature may be prevented from burningv under ordinary conditions and rendered non-inflammable provided there is present in suitable combination a heat absorbing compound capable of absorbing or taking up through decomposition, volatilization, or other change, all or the major part of the heat that would be necessary to raise the material or its combe sustained.

This heat absorbing, or endothermic, substance or com ound should be of such nature that it will, ecom ose, or otherwise be in condition to absor heat, before or when the temperature of combustion of the material to be rendered non-inflammable has been reached. The absorption of heat will thus roceed at such a rate as to prevent the complastics, pyroxylin ponents to the point at which ignition could substance, will be variedi somewh at, to meet conditionsv of strength, plasticity transparency, or other desirablecharacteristics, but

in general will be: "depen k lent 'upon the amount 10f decomposition, j in heat Cunit equivalents, that can take place, at or 'below the temperature at which combustion could be sustained by the "exothermic"compound if the heat of combustion werefnotabsorbed should be employed to abso'rbi upon its decomposition a sufficientfamount of heat to prevent a sustained combustion of the said. exothermic substance. for is that which will not permit of a self- In carrying out my invention,'any one of a number of productsmay betheaim.-- The cutting out various objects such; as brush backs, mirror backs, knife handles, etc, to.

that of a thin, highly'flexible' product which may be used for the veneering. of; fabrics, paper and the like orwhich can belu'sedin place of various: textilesf and other flexible materials. The flexible compound mayalso be used as a substitute for leather. It may also possess the necessary characteristics required in compounds that are to be molded such as molded boxes, molded handles, molded brushes, mirrors, etc.

In carrying out the invention the procedure will vary according to the nature and physical properties of the material treated.

The exothermic substance which I propose to use will be nitrocellulose, acetylcellulose com ound.

T e permanent or non-volatile solvents, generally referred to as the plasticizing or some cellulosic ester, ether, derivative or agents and which are to be combined with -the pyroxylin or other cellulose derivative for the purpose of bringing about the necessary, conversion, etc., in the course of manufacture, should be of such nature that the point of ignition is relatively high. In my experiments I have found that the organic phosphates possess the necessary characteristics of solubility and at the same time possess the requisite temperature of ignition.

The most satisfactory results are produced with the aromatic phosphates because of their relatively high stability and resistance to decomposition, and because they possess at the same time the necessary solvent or plasticizing effect on the nitrocellulose, as Well as a relatively high ignition point.

To a mixture of nitrocellulose and an aromatic phosphate, as for example, liquid tricresylphosphate, I add a sufficient amount of calcium tartrate to prevent the combined mixture from sustaining ignition upon the application and withdrawal of. a flame. An

- example of proportions; for this purpose is 100 parts of acetylcellulose, 15 to 30 parts of liquid tricresylphosphate, and to 50 parts of calcium tartrate (OaC,H,O -4H,O).

Material of this composition, when manufactured according to the usual methods as obtain in the pyroxylin plastic industry, will 7 possess hardness, toughness and moldability 20 in similar degree to the usual varities of celluloid, manufactured in the form of ivory,

opaque colors and the like.

In the manufacture of these non-inflammable compounds I proceed substantially as in the manufacture of ordinary pyroxyhn plastic materials incorporating the calcium.

Patent No. 1,233,374, granted July 1 1917.

In the choice of liquid volatile solvent, 1 may select any one of a c mbination of a number of the common orhinary solvents, such as methyl alcohol,-ethyl alcohol, acetic ether, acetone, amyl acetate, or the various commercial grades and mixtures of these compounds as are ordinarily found upon the market.

In the manufacture of the flexible non-inflammable compound having the properties of leather and the like, I proceed as in the example specified except that I increase the proportion of liquid tricresylphosphate somewhat. Material of this composition may be Worked up according to the usual method for the manufacture of pyroxylin plastic compounds and produced in the form of sheets by shaving from a block, or it may be dissolved in a suitable proportion of solvent such as wood alcohol, acetone and the like and spread upon a suitable surface such as textile fabric, leather and the like.

This application is a division of my application Ser. No. 556,531, filed April 25, 1922.

I claim:

1. A composition comprisinga cellulose acetate and calcium tartrate in sutficient quantity to produce a fire retarding effect.

2.- A composition containing cellulose acetate, a plasticizer therefor containing an aromatic phosphate and a fire retarding ingredient comprising calcium tartrate.

3. A composition containing cellulose acetate, a plasticizer therefor containing tricresylphosphate and a fire retarding ingredient comprising calcium tartrate. 

